(x+1)(x-1)=______; (x-1)2=______.
(x+1)(x-1)=x2-1;(x-1)2=x2-2x+1.
故答案为:x2-1;x2-2x+1
—Will you attend the meeting this afternoon?
—But I ________ told anything about it.
A.haven't been
B.am not
C.wasn't
D.won’t be
()是昆虫的2个体段。
A.胸部
B.腹部
C.头部
D.体壁部